From b40b3ddcfcd114f6e67de6e05c3afd77d5de8406 Mon Sep 17 00:00:00 2001
From: Dale Curtis <dalecurtis@chromium.org>
Date: Tue, 28 Nov 2017 14:26:55 -0800
Subject: [PATCH] Don't manipulate duration when it's AV_NOPTS_VALUE.

This leads to signed integer overflow.

Signed-off-by: Dale Curtis <dalecurtis@chromium.org>
Signed-off-by: James Almer <jamrial@gmail.com>
(cherry picked from commit c5fd57f483d2ad8e34551b78509f1e14136f73c0)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavformat/oggparsevp8.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/oggparsevp8.c b/libavformat/oggparsevp8.c
index 5959d32b6a..e3ca775d22 100644
--- a/libavformat/oggparsevp8.c
+++ b/libavformat/oggparsevp8.c
@@ -116,7 +116,7 @@ static int vp8_packet(AVFormatContext *s, int idx)
         os->lastpts = os->lastdts = vp8_gptopts(s, idx, os->granule, NULL) - duration;
         if(s->streams[idx]->start_time == AV_NOPTS_VALUE) {
             s->streams[idx]->start_time = os->lastpts;
-            if (s->streams[idx]->duration)
+            if (s->streams[idx]->duration && s->streams[idx]->duration != AV_NOPTS_VALUE)
                 s->streams[idx]->duration -= s->streams[idx]->start_time;
         }
     }